Conventional methods for producing γ-valerolactone by bringing a levulinic acid compound into contact with hydrogen, for example, the following methods.
For an example, Patent Literature 1 describes a method for producing γ-valerolactone by reacting levulinic acid or its ester with hydrogen in the presence of a carbonyl complex of ruthenium or iron.
For another example, Patent Literature 2 describes a method for producing γ-valerolactone by reacting levulinic acid with hydrogen in the presence of an iridium-, palladium-, platinum-, rhenium-, rhodium- or ruthenium-supported catalyst.
For still another example, Patent Literature 3 describes a method for producing γ-valerolactone by reacting levulinic acid with hydrogen in the presence of a ruthenium catalyst supported on activated carbon and 0.08% water relative to levulinic acid by weight.
For still another example, Patent Literature 4 describes a method for producing γ-valerolactone by reacting levulinic acid or its ester with hydrogen in the presence of an oxide composite made of copper oxide and aluminum oxide.